Inverter-integrated electric compressors, which integrally incorporate inverter devices, are used as air conditioner compressors installed in electric vehicles, hybrid vehicles, and the like. This inverter-integrated electric compressor converts high-voltage DC power supplied from a power supply unit installed in a vehicle to three-phase AC power of a required frequency by the inverter device, and then applies this power to an electric motor to drive the electric motor.
The inverter device is provided with high-voltage electrical components such as a coil and a smoothing capacitor that constitute a filter circuit, and a plurality of semiconductor switching elements that constitute a switching circuit which converts electricity, an inverter substrate on which inverter circuits, including the filter circuit and the switching circuit, and control circuits of the inverter circuits are mounted, a substrate on which a communication circuit is mounted into which control signals from a host control device (ECU) are input, and the like. The inverter device is configured to convert DC that is input from a power supply unit to a P-N terminal via the power source cable to three-phase AC power and to output the three-phase AC power via a UVW busbar or the like.
The inverter device is integrated with the electric compressor by being incorporated into an inverter housing portion provided to the housing outer periphery of the electric compressor, and is configured to apply the three-phase AC power output via the UWV busbar or the like to an electric motor inside the housing, via a motor terminal that is provided in the inverter housing portion so as to pass through the housing. In Patent Document 1, a device is disclosed that outputs AC power, which is converted by an inverter module, to a motor terminal via a UVW busbar that is integrally insert-molded using a resin material.
Further, the inverter substrate is normally supported inside the inverter housing portion via a support leg, a bolt, or the like, and inverter components such as capacitors, coils, and semiconductor switching elements are mounted on the substrate by their terminals connected to the substrate. In Patent Documents 2 and 3, devices are disclosed that incorporate an inverter device in which these inverter components are disposed between the inverter substrate and a bottom surface of the inverter housing portion.